Powder-grain.



No. 654,47l. Patented luly 24, I900.

H. S. MAXIIL- POWDER GRAIN.

(Application fllod June 86, 1899.)

(No Model.)

' UNITED "STATES PATENT'OFFIQE,

HlRAM STEVENS MAXIM, orLoNnoN, EN nnmtnssicnon 'ro'run vicnnns, SuNs a MAXIM, I.ll\ll'lEI),'()F SAME PLACE.

POWDER- GRAIN.

SPECIFICATION forming part of Letters Patient N0. 654,471, dated. July 24, 1900. Application tiled June 28, 1899. Serial No. 721.915- (No specimens.)

To all whom, it may concern Be it known that I, llmen STEVENS MAXIM, chevalior of the Legion of Honor, civil and mechanical engineer, a citizen of the United States, rusidingat 1S Queens Gate Place, London, in the county of Middlcsex, England, have invented certain new and useful Improvements in the Manufacture of Explosives, of which the following is a specification.

This invention has reference to the manufacture of explosives for artillery.

It is well known that the prod nets of combustion of cordite and ballistite used in some of the naval andmilitary services consist largely of carbon dioxide, a very heavy and dense gas, which by reason of its great heat erodes the barrels of guns much more rapidly than carbon monoxide. It-is therefore advantageous to have as little as possible of the carbon dioxide present in the products of combustion. In fact, it is better to produce a little smoke than to erode the gun too much. It is possible to prevent or diminish the erosion of the gun by making one of the constituents of the explosive.of some resinous or other hydrocarbonaceous substance that will cause the evolution of carbon monoxide instead of carbon dioxide when the explosive is fired. The resinous material I prefer to use is American resin mixed with about oneseventh part of its weight of oil, such as that used for lubricating engine-cylinders. I do not, however, wish to con tine myself to these substances.

Many nations object to the use of nitroglycerine as a constituent of their smokeless explosives for artillery purposes and prefer to make them from guncotton, (trinitro-cellulose.) \Vhen, however, a smokeless explosive is made altogether from gun-cotton by dissolving'tho latter in the well-known manner, the explosive in its finished condition is liable to be very hard and to burn too slowly for artillery purposes. 1 f, on the other hand, the explosive be made from pulped guncotton--that is to say, with the cotton in a fibrous condition-it is found that the explosive burns too rapidly.

According to my invention the required progressive action of the explosive may be best obtained by making each particular block, gram, or tablet of the explosive compound in several pieces -that is to say,on'e or more e'xterior shells of an extremely-slow-burningehar actor and great density and an interior disk made of a quick-burning character and fibrous nature. The several pieces being put together in a mold and pressed are converted into a single block or tablet the exterior part of which is slow-burning and the interior quick-burn- 6o ing. In some cases the blocks may be subjected to comparatively-light pressure while wet and then dried and heated and subjected to further compression'after the drying, or the further compression may be effected after the blocks or the fibrous portions thereof have been submitted to the action of solvents in a vacuum or otherwise.

In the accompanying drawings, Figures 1 and 2 are respect-rely a plan and a transverse section of a talv ;t of the explosive made in disk f'orm.

Referring to Figs. 1 and 2, the tabletis made in the shape of'a disk, with a series of concentric ann ular depressions aain each face thereof, the portions between the said annular depressions being formed with tapered cavities or indentations b b. The indentations in'one face preferably break joint with those in the other, as shown. This form of the blocks or tablets permits their having a large area of bu rning'surface without the liability that 'exists with ordinary multiple-perforated blocks of accumulating sufficient pressure when the powder is fired in the gnnto blow the blocks into atoms.

What I claim is- A nitro-componnd explosive composed of the described ingredien'ts'and formed into the shape of a block having concentric annular 9o depressions in each face thereof with tapered cavities formed in the walls separating said depressions, the said cavities on one side of the block breaking joint with those on the other side, substantially as and for the purpose specified.

In testimony whereof I have hereunto set my hand, in presence of two subscribing witnesses, this 15th day of June, 1899.

IIIRAM STEVENS MAXIM.

Witnesses: a

J. COLLINS, WALTEa J. Sanarnn. 

